Comparing the new Raspberry Pi 2 with the Odroid-C1

Competitive Edge

Dr. Udo Seidel

A user wanting to buy a nano-computer might think that performance is all that matters. Comparing the Raspberry Pi 2 with the powerful newcomer Odroid-C1 shows that it is a good idea to consider other features as well.

The Raspberry Pi clearly opened up the consumer market for an inexpensive ARM computer. However, the size of its main memory and its network speed limited the number of applications it was suitable for, thus creating an opportunity for competitors to get into the market.

The Raspberry Pi Foundation didn't leave its users out in the cold, however, but instead kept developing its product. Model B followed Model A, and then A+ and B+, and now finally version 2 [1]. Currently, the newest competitor for the Rasp Pi is a nano-computer named Odroid-C1. This board is made by a company out of South Korea called Hardkernel [3], which has already attracted attention for its Odroid models U3 and XU3.

Preparations

Earlier this year, demand was high for both of these new small-board computers (SBCs). Beginners wanting to purchase one should look for a ready-to-use package that contains all the necessary components (e.g., covers, power supply, and possibly even a microSD card) in addition to the board.

Odroid's North American distributor ameriDroid offers several SBCs and accessories [4]. If you prefer buying components individually, you should make sure to get the correct power connectors, because each board has a different power supply. Raspberry Pi customers will most probably need an additional power supply when purchasing an Odroid-C1 unless they already own other boards from Hardkernel. The power supply from an older Hardkernel board can be utilized for the new board.

Both devices use a microSD card for mass storage. The Odroid-C1 also accepts eMMC storage. A case is not necessary in the beginning, and in some situations, a case can even be a hindrance for a Hardkernel ARM nano-computer because the microSD slot is found in the center of the underside of the board (Figure 1). Perhaps somebody will come up with a nifty design for a cover that both protects the device and lets the user exchange the card easily.

Figure 1: Top (left) and bottom (right) views of an Odroid-C1 on the left and a Raspberry Pi 2 on the right. The microSD slot on the Odroid is placed in a peculiar location.

If you already have a cover for the Rasp Pi B+, you can continue using it for the updated model. Tests show, however, that modification may be required. For example, the cutout for the SD card slot on some of the covers was so skimpy that it was not possible to take a card out once it had been put in. Table 1 provides an overview of the technical details for both of the computers.

Table 1

Specifications

Feature

RPi2

Odroid-C1

ARM model

ARMv7

ARMv7

Family

Cortex-A7

Cortex-A5

CPU type

Broadcom BCM2836 (0.9GHz)

Amlogic S805 (1.5GHz)

Number of cores

4

4

GPU

Broadcom VideoCore IV

ARM Mali 450MP

RAM

1GB

1GB

Network

100Mbps

1,000Mbps

USB

4x 2.0, 1x OTG

4x 2.0, 1x Micro

WiFi/Bluetooth

– /--

– /--

IR

–

Yes

Storage medium

MicroSD

MicroSD/eMMC

Video

HDMI

Micro HDMI

Audio

Via HDMI

Via micro HDMI

Real-time clock (RTC)

–

Yes

Size (mm)

85x56x38

85x56x38

GPIO

2x 20-pin (UART/SPI/I2C/ADC)

2x 20-pin (UART/SPI/I2C/I2S)

Price

$35.00

$37.95

System

The current selection of suitable operating systems for the Odroid-C1 is meager. Aside from Android 4.4.2, the board merely supports Ubuntu 14.04.1 LTS and then only in a minimal form or with a graphical interface. Interestingly, both use different kernel versions that include 3.10.66-49 for the minimal version and 3.10.67-55 for the fully equipped. A new version of RISC OS also boots on the Odroid. However, the system only returns one ping and does not react to access via SSH.

The available selection of systems for the new Rasp Pi is likewise growing slowly. The most important of the current systems are Raspbian and Ubuntu Snappy Core. Microsoft has announced that it plans a Windows 10 version for the new Raspberry Pi, but that remains to be seen. Users interested in finding out what Microsoft has in mind should register for the developer program for the Internet of Things [5].

The Raspberry Pi board is basically built to be backward compatible, which means operating systems for previous generations should be suitable for the new version of the hardware. However, users will find that the devil is in the details. A few systems carry different images [6] for the different Rasp Pi versions. For example, OpenELEC has ARM11 and ARMv7 images [7].

The guidelines for downloading RISC OS [8] and OSMC (the Raspbmc successor) [9] indicate that Rasp Pi version 2 Model B (RPi2B) is supported. Pidora [10] only works with the Rasp Pi version 1 (RPi1); however, a Fedora 21 Remix has been developed for the RPi2B [11].

A behind-the-scenes look at Raspbian shows that the modifications that have been made are limited in scope. In fact, most of the packages have not been changed. The adaptations undertaken for the RPi2B took place in the core of the operating system. The version of the kernel is identical except that it has now been compiled for the new architecture. The summary box titled "What's New with the RPi2B" lays out the details of the hardware innovations for the RPi2B.

What's New with the Rpi2B

A basic shortcoming of the Rasp Pi models has always been the somewhat outdated version 6 of the ARM architecture. Because of the lack of support for large distributions, the Raspberry Pi foundation has replaced the Broadcom BCM2835 with a BCM2836 on the current board. This BCM2836 system is compatible with the ARMv7 architecture.

As a consequence of replacing the chip, the number of cores also increased from one to four, and the clock rate increased from 700MHz to 900MHz. The new processor belongs to the family of so-called Cortex-A chips that are particularly suited for applications. The RPi2B uses a Cortex-A7.

The second modification consists of a change in the size of the main memory. At 1GB, this is twice as large as the main memory in the B/B+ versions of the first generation. This upgrade makes it possible to run several programs simultaneously without causing interference in main memory.

All of the other connectors, the form factor, and the board layout for the RPi2B have been taken from the RPi1B+. Hopes for an increase in network speed have proven futile. The new version has kept the previous limit of 100Mbps.

Even with a little bit of Android in Odroid, the small computer works equally well with Linux. In this article, we examine the aspiring quad-core SBC and introduce the most important firmware packages.

Our cover says "Boards Galore!", and we're not kidding. Last issue, we reviewed the LeMaker HiKey and the Banana Pi M3. This issue we add the Odroid-C2, Pine A64+, LeMaker Guitar, BBC micro:bit, and C.H.I.P. Each of these small-board computers (SBCs) have strengths and weaknesses, so you have to understand the needs of your project to choose wisely.

The maker movement just keeps getting stronger, and open hardware and software are right in the middle, combining electronics, code, construction kits, and bits and pieces of whatever's in the spare parts bin to create something new or remake something old.